Micro and Macro Hardness Measurements, Correlations, and Contact Models

Brief reviews of Brinell (Meyer) and Rockwell indenters and macrohardness tests, Berkovich, Knoop and Vickers indenters and microhardness tests, and nanoindentation tests using the Berkovich indenter are given. Vickers, Brinell and Rockwell C indentation results for Ni 200, SS 304, Zr-4, and Zr-Nb are reported and correlation equations for micro and macrohardness versus penetration depth are given. Temperature eects on yield strength, Brinell and Vickers hardness are given and correlation equations are presented to account for elevated temperatures. Models are presented for calculation of the appropriate value of contact microhardness which depends on apparent contact pressure and the eective surface roughness of the joint. Examples are given to illustrate the use of the correlation equations.